The apparatus of anesthetic technology should provide the possibility of permitting different anesthetic mediums to be utilized as required by means of change-over switching. It should be possible to introduce the anesthetic mediums with the same precision either into the fresh gas flow or directly into the patient system.
Published German patent application DE-OS No. 31 16 951 discloses an arrangement for adding liquid anesthetic medium into the respiratory gas to be supplied to a patient and contains a heatable swirl chamber into which the anesthetic medium is fed with the aid of a pump from the tank holding the anesthetic medium. The anesthetic medium enters the swirl chamber tangentially with the stream of respiratory gas where it develops into a cyclone-like flow and is vaporized. A heater of the swirl chamber is controlled with the aid of a temperature sensor and provides the heat needed for vaporization. The respiratory gas flows out again through an outlet whereat its temperature is checked. The respiratory gas now enriched with the anesthetic medium is then supplied to the patient. A control and evaluation circuit connected to sensors conducts the measurements and releases an alarm or controls when deviations from desired values was detected.